Text preview for : 7B92A Dual Time Base (service) (Oscilloscope Plugin) (Mil TM 11-6625-2925-24) (1980) WW.pdf part of
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ARMY TM 11-6625-2925-24
AIR FORCE TO 33A1-10-242-2
ORGANIZATIONAL, DIRECT SUPPORT, AND GENERAL SUPPORT
MAINTENANCE MANUAL
DUAL TIME BASE, TEKTRONIX MODEL 7B92A
(NSN 6625-01-027-0265)
DEPARTMENTS OF THE ARMY AND THE AIR FORCE
21 JULY 1980
WARNING
DANGEROUS VOLTAGES EXIST IN THIS EQUIPMENT
Dangerous potentials exist at several points throughout this equipment. When the equipment is operated
with the covers removed DO NOT touch exposed connections or components. Some transistors have
voltages present on their cases. Disconnect power before cleaning the equipment or replacing parts.
DON'T TAKE CHANCES!
Copyright 1974 (new material 1978) by Tektronix Inc.
REPRODUCED BY PERMISSION OF THE COPYRIGHT OWNER, TEKTRONIX INC.
TM 11-6625-2925-24
TO 33A1-10-242-2
Technical Manual ) DEPARTMENTS OF THE ARMY
No. 11-6625-2925-24 ) AND THE AIR FORCE
TO 33A1-10-242-2 ) Washington, DC, 21 July 1980
ORGANIZATIONAL, DIRECT SUPPORT, AND GENERAL SUPPORT
MAINTENANCE MANUAL
DUAL TIME BASE, TEKTRONIX MODEL 7B92A
(NSN 6625-01-027-0265)
REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS
You can help improve this manual. If you find any mistakes or if you know of a way to improve the
procedures, please let us know. Mail your letter or DA Form 2028 (Recommended Changes to
Publications and Blank Forms) direct to: Commander, US Army Communications and Electronics
Materiel Readiness Command and Fort Monmouth, ATTN: DRSEL-ME-MQ, Fort Monmouth, New Jersey
07703.
For Air Force, submit AFTO Form 22 (Technical Order System Publication Improvement Report and
Reply) in accordance with paragraph 6-5, Section VI, T.O. 00-5-1. Forward direct to prime ALC/MST.
In either case, a reply will be furnished direct to you.
TABLE OF CONTENTS
Page
SECTION 0 INTRODUCTION
Scope ............................................................................................................................................ 0-1
Indexes of Publications ................................................................................................................. 0-1
Maintenance Forms, Records, and Reports ................................................................................. 0-1
Reporting Equipment Improvement
Recommendations (EIR)............................................................................................................ 0-1
Destruction of Army Electronics Materiel ...................................................................................... 0-1
i
7B92A
TABLE OF CONTENTS
Page
LIST OF ILLUSTRATIONS........................................................................................................... v
SAFETY SUMMARY..................................................................................................................... vii
SECTION 1 OPERATING INSTRUCTIONS
INTRODUCTION........................................................................................................................... 1-1
INSTALLATION............................................................................................................................. 1-1
FRONT-PANEL CONTROLS, CONNECTORS, AND INDICATORS ........................................... 1-2
Main Triggering Controls............................................................................................................ 1-2
Sweep Controls.......................................................................................................................... 1-4
Delayed Triggering Controls ...................................................................................................... 1-5
Front-Panel Inputs...................................................................................................................... 1-5
FUNCTIONAL CHECK.................................................................................................................. 1-5
Setup Procedure ........................................................................................................................ 1-6
Sweep Functions........................................................................................................................ 1-6
Triggering Functions .................................................................................................................. 1-7
GENERAL OPERATING INFORMATION..................................................................................... 1-8
Main Triggering .......................................................................................................................... 1-8
Main Trigger Modes ................................................................................................................... 1-8
Main Trigger Coupling................................................................................................................ 1-9
Main Trigger Source................................................................................................................... 1-10
Input Impedance ........................................................................................................................ 1-10
Trigger Slope.............................................................................................................................. 1-10
Trigger Level .............................................................................................................................. 1-10
Selecting Sweep Rates .............................................................................................................. 1-12
Time Measurement .................................................................................................................... 1-12
Display Modes............................................................................................................................ 1-12
Delay Time Multiplier.................................................................................................................. 1-13
Delayed Sweep Triggering......................................................................................................... 1-13
SECTION 2 SPECIFICATION........................................................................................................................... 2-1
THE FOLLOWING SERVICING INSTRUCTIONS ARE FOR USE BY QUALIFIED PERSONNEL ONLY.
TO AVOID PERSONAL INJURY, DO NOT PERFORM ANY SERVICING OTHER THAN THAT
CONTAINED IN OPERATING INSTRUCTIONS UNLESS YOU ARE
QUALIFIED TO DO SO.
SECTION 3 THEORY OF OPERATION
Block Diagram Description ............................................................................................................ 3-1
Detailed Circuit Description ........................................................................................................... 3-1
Main Trigger Generator ............................................................................................................ 3-1
Delaying Sweep Generator ...................................................................................................... 3-3
Delayed Trigger Generator....................................................................................................... 3-4
Delayed Sweep Generator ....................................................................................................... 3-6
Horizontal Logic........................................................................................................................ 3-6
Output Amplifier........................................................................................................................ 3-7
Readout .................................................................................................................................... 3-7
@
ii
7B92A
TABLE OF CONTENTS (cont)
SECTION 4 MAINTENANCE............................................................................................................................ Page
Preventive Maintenance................................................................................................................ 4-1
Cleaning ................................................................................................................................... 4-1
Visual Inspection ...................................................................................................................... 4-1
Lubrication ................................................................................................................................ 4-1
Semiconductor Checks ............................................................................................................ 4-2
Adjustment After Repair ........................................................................................................... 4-2
Troubleshooting............................................................................................................................. 4-3
Troubleshooting Aids................................................................................................................ 4-3
Troubleshooting Equipment ..................................................................................................... 4-6
Troubleshooting Techniques .................................................................................................... 4-6
Corrective Maintenance ................................................................................................................ 4-8
Obtaining Replacement Parts .................................................................................................. 4-8
Soldering Techniques............................................................................................................... 4-8
Component Removal and Replacement .................................................................................. 4-9
Adjustment After Repair ........................................................................................................... 4-11
Repackaging For Shipment...................................................................................................... 4-11
SECTION 5 PERFORMANCE CHECK/CALIBRATION
Preliminary Information ............................................................................................................ 5-1
Test Equipment Required......................................................................................................... 5-1
Part I Performance Check ............................................................................................................. 5-4
Outline for Part I Performance Check ...................................................................................... 5-4
A. Trigger Sensitivity........................................................................................................... 5-4
B. Horizontal System .......................................................................................................... 5-4
Preliminary Procedure.............................................................................................................. 5-4
A. Trigger Sensitivity................................................................................................................ 5-5
B. Horizontal System............................................................................................................... 5-10
Part II Calibration........................................................................................................................... 5-16
Outline for Part II Calibration .................................................................................................... 5-16
A. Trigger Sensitivity (SN B070000-above)........................................................................ 5-16
B. Trigger Sensitivity (SN B069999-below) ........................................................................ 5-16
C. Horizontal System.......................................................................................................... 5-17
Preliminary Procedure ......................................................................................................... 5-17
A. Trigger Sensitivity (SN B070000-above)............................................................................. 5-18
B. Trigger Sensitivity (SN B069999-below) ............................................................................. 5-25
C. Horizontal System............................................................................................................... 5-33
SECTION 6 OPTIONS
SECTION 7 REPLACEABLE ELECTRICAL PARTS
SECTION 8 DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS
SECTION 9 REPLACEABLE MECHANICAL PARTS
Change Information
@
iii
TM 11-6625-2925-24/TO 33A1-10-242-2
TABLE OF CONTENTS (CONT)
Page
APPENDIX A REFERENCES................................................................................................................. A-1
APPENDIX B MAINTENANCE ALLOCATION
Section I. Introduction....................................................................................................................... B-1
II. Maintenance Allocation Chart for Dual Time
Base, Tektronix Model 7B92A..................................................................................... B-3
III. Tool and Test Equipment Requirements for Dual
Time Base, Tektronix Model 7B92A............................................................................ B-4
IV. Remarks ........................................................................................................................... B-5
APPENDIX C REPAIR PARTS AND SPECIAL TOOLS LIST (RPSTL)
(Not applicable)
APPENDIX D EXPENDABLE SUPPLIES AND MATERIALS LIST
(Not applicable)
iv
7B92A
LIST OF ILLUSTRATIONS
Figure No. Page
Frontispiece 7B92A Dual Time Base
1-1 Location of Variable and Mainframe Selector multi-pin connectors ....................................... 1-1
1-2 Location of release latch......................................................................................................... 1-2
1-3 Front-panel controls and connectors ...................................................................................... 1-3
1-4 Effect of MAIN TRIGGERING LEVEL and SLOPE controls on crt display............................. 1-11
1-5 Area of graticule used for most accurate time measurements ............................................... 1-12
1-6 Typical alternate sweep display.............................................................................................. 1-13
2-1 Dimensional drawing............................................................................................................... 2-5
4-1 Lubrication procedure for a typical cam switch....................................................................... 4-2
4-2 Semiconductor lead configurations......................................................................................... 4-4
4-3 Inter-board multi-pin connector assembly............................................................................... 4-5
4-4 End-lead multi-pin connector assembly.................................................................................. 4-5
4-5 Location of pin numbers of Interface connector ..................................................................... 4-5
5-1 Main Triggering level range .................................................................................................... 5-6
5-2 Delayed Triggering level range............................................................................................... 5-6
5-3 Variable Time/Division range.................................................................................................. 5-13
5-4 Fast delay time accuracy ........................................................................................................ 5-14
5-5 DC balance. (Circle denotes correct trigger point.)................................................................ 5-19
5-6 Trigger Sensitivity. (Circle denotes correct trigger point.)...................................................... 5-19
5-7 Main Triggering level range. (Circle denotes triggering limits.).............................................. 5-19
5-8 Delayed Triggering level range. (Circle denotes triggering limits.) ........................................ 5-21
5-9 DC balance. (Circle denotes correct trigger point.)................................................................ 5-26
5-10 Trigger sensitivity. (Circle denotes correct trigger point.) ...................................................... 5-26
5-11 Main Triggering level range. (Circle denotes triggering limits.).............................................. 5-27
5-12 Delayed Triggering level range. (Circle denotes triggering limits.) ........................................ 5-29
5-13 Correct DTM Scale and Delay Start adjustment (circle) ......................................................... 5-34
5-14 Variable Time/Division range.................................................................................................. 5-38
5-15 Fast delay time accuracy ........................................................................................................ 5-39
v
7B92A
LIST OF ILLUSTRATIONS (cont)
The illustrations in Section 8 are located near their associated
diagrams on the foldout pages.
Figure No.
8-1 Circuit board locations
8-2 Block diagram
8-3 A3 Coupling Switch circuit board
8-4 A5 Delayed Triggering Switch circuit board
8-5 A2 Source Switch circuit board
8-6 A4 Mode Switch circuit board
8-7 Al External Input circuit board
8-8 A8 Main Trigger circuit board (SN B070000-above)
8-9 A8 Main Trigger circuit board (SN B069999-below)
8-10 A9 Delayed Trigger circuit board (SN B070000-above)
8-11 A9 Delayed Trigger circuit board (SN B069999-below)
8-12 A6 Interface circuit board
8-13 A6 Interface circuit board
8-14 A6 Interface circuit board
8-15 A7 Logic circuit board (SN B059999-below)
8-16 A7 Logic circuit board (SN B060000-above)
8-17 A12 Readout circuit board
8-18 Location of Sweep Timing adjustments
8-19 Location of Main Trigger adjustments (SN B069999-below)
8-20 Location of Delayed Trigger adjustments (SN B069999-below)
8-21 Location of Main Trigger adjustments (SN B070000-above)
8-22 Location of Delayed Trigger adjustments (SN B070000-above)
LIST OF TABLES
Table No. Page No.
2-1 Electrical Characteristics .......................................................................................................................... 2-1
2-2 Environmental ........................................................................................................................................... 2-4
2-3 Physical..................................................................................................................................................... 2-4
3-1 7B92A Readout Character Selection........................................................................................................ 3-8
5-1 Test Equipment......................................................................................................................................... 5-2
5-2 Sweep Timing ........................................................................................................................................... 5-11
5-3 Fast Timing ............................................................................................................................................... 5-12
5-4 Fast Sweep Linearity................................................................................................................................. 5-12
5-5 Differential Delay Time Accuracy.............................................................................................................. 5-13
5-6 Fast Differential Delay Time Accuracy...................................................................................................... 5-14
5-7 Sweep Timing ........................................................................................................................................... 5-36
5-8 Fast Timing ............................................................................................................................................... 5-37
5-9 Fast Sweep Linearity................................................................................................................................. 5-37
5-10 Differential Delay Time Accuracy.............................................................................................................. 5-39
5-11 Fast Differential Delay Time Accuracy...................................................................................................... 5-39
@
vi
7B92A
SAFETY SUMMARY
This manual contains safety information that the user must follow to ensure safe operation of this instrument.
WARNING information is intended to protect the operator; CAUTION information is intended to protect the instrument.
The following are general safety precautions that must be observed during all phases of operation and maintenance.
Ground the Instrument
To reduce electrical-shock hazard, the mainframe (oscilloscope) chassis must be properly
grounded. Refer to the mainframe manual for grounding information.
Do Not Operate in Explosive Atmosphere
Do not operate this instrument in an area where flammable gases or fumes are present. Such
operation could cause an explosion.
Avoid Live Circuits
Electrical-shock hazards are present in this instrument. The protective instrument covers must
not be removed by operating personnel. Component replacement and internal adjustments must
be referred to qualified service personnel.
Do Not Service or Adjust Alone
Do not service or make internal adjustments to this instrument unless another person, capable of
giving first aid and resuscitation, is present.
Warning Statements
Warning statements accompany potentially dangerous procedures in this manual. The following
warnings appear in this manual and are listed here for additional emphasis.
To avoid electrical shock, disconnect the instrument from the power source before soldering.
To avoid electrical shock, disconnect the instrument from the power source before replacing
components.
Handle silicone grease with care. Avoid getting silicone grease in eyes. Wash hands thoroughly
after use.
@
vii
7B92A
REV B, JUN 1978
viii
TM 11-6625-2925-24/T0 33A1-10-242-2
SECTION 0
INTRODUCTION
0-1. Scope
This manual contains instructions for organizational, direct support, and general support maintenance of Dual
Time Base, Tektronix Model 7B92A. Throughout this manual Dual Time Base, Tektronix Model 7B92A is referred to as
the 7B92A.
0-2. Indexes of Publications
a. DA Pam 310-4. Refer to the latest issue of DA Pam 310-4 to determine whether there are new editions,
changes, or additional publications pertaining to the equipment.
b. DA Pam 310-7. Refer to DA Pam 310-7 to determine whether there are modification work orders (MWO's)
pertaining to the equipment.
0-3. Maintenance Forms, Records, and Reports
a. Reports of Maintenance and Unsatisfactory Equipment. Department of the Army forms and procedures used
for equipment maintenance will be those prescribed by TM 38-750, The Army Maintenance Management System (Army).
Air Force personnel will use AFM 66-1 for maintenance reporting and TO-00-35D54 for unsatisfactory equipment
reporting.
b. Report of Packaging and Handling Deficiencies. Fill out and forward DD Form 6 (Packaging Improvement
Report) as prescribed in AR 735-11-2/NAVSUPINST 4440.127E/AFR 400-54/MCO 4430.3E and DSAR 4140.55.
c. Discrepancy in Shipment Report (DISREP) (SF 361). Fill out and forward Discrepancy in Shipment Report
(DISREP) (SF 361) as prescribed in AR 55-38/NAVSUPINST 4610.33B/AFR 75-18/MCO P4610.19C and DLAR 4500.15.
0-4. Reporting Equipment Improvement Recommendations (EIR)
a. Army. If your 7B92A needs improvement, let us know. Send us an EIR. You, the user, are the only one who
can tell us what you don't like about your equipment. Let us know why you don't like the design. Tell us why a procedure
is hard to perform. Put it on an SF 368 (Quality Deficiency Report). Mail it to Commander, US Army Communications and
Electronics Materiel Readiness Command and Fort Monmouth, ATTN: DRSEL-ME-MQ, Fort Monmouth, New Jersey
07703. We'll send you a reply.
b. Air Force. Air Force personnel are encouraged to submit EIR's in accordance with AFM 900-4.
0-5. Destruction of Army Electronics Materiel
Destruction of Army electronics materiel to prevent enemy use shall be in accordance with TM 750-244-2.
0-1
Section 1-7B92A
OPERATING INSTRUCTIONS
INTRODUCTION INSTALLATION
The 7B92A Dual Time Base unit provides The 7B92A is designed to operate in the
normal, delayed, intensified, and alternate sweep horizontal plug-in compartment of the oscilloscope. This
operation for TEKTRONIX 7000-Series Oscilloscopes. instrument can also be installed in a vertical plug-in
Calibrated sweep rates from 0.2 second to 0.5 compartment to provide a vertical sweep on the crt.
nanosecond and triggering to 500 megahertz are However, when used in this manner, there are no
provided. The 7B92A is intended for use with high- internal triggering or retrace blanking provisions, and the
frequency 7000-Series Oscilloscope systems; however, unit may not meet the specifications given in the
most 7B92A functions are compatible with all 7000- Specification section of this manual.
Series Oscilloscopes.
Before proceeding with installation, check the
Other features include lighted pushbutton settings of the Time/Div Variable Selector multi-pin
switches, compatibility with indicator oscilloscopes connector and the Mainframe Selector multi-pin
having an alphanumeric readout system, and 0 to 9.8 connector (see Fig. 1-1). The Time/Div Variable
times continuous sweep delay. A VARIABLE control Selector determines whether the front-panel Time/Div
allows continuously variable sweep rates between VARIABLE control operates in conjunction with the
calibrated steps. Also, when operating in the AUTO delaying or delayed sweeps. The Mainframe Selector
MAIN TRIGGERING Mode, a bright base line is adapts the 7B92A to the oscillsocope mainframe being
displayed in the absence of a trigger signal. used. The two mainframe selections are:
This section describes the operation of the front- 1. 7800 and 7900-Series Oscilloscopes.
panel controls and connectors, and provides a functional
check and general operating information for this 2. All other 7000-Series Oscilloscopes.
instrument.
NOTE
NOTE
The 7B71 will not delay the 7B92A for
The ALT OFF position, which allows displaying alternating Delaying and
the Intensified mode of operation, is Delayed sweeps. Instead, it causes a
applicable to instruments SN sweep lock-up to occur under the
B060000-above. following conditions; with the 7B71 in
the A horizontal compartment
Fig. 1-1. Location of Variable and Mainframe Selector multi-pin conectors.
REV B, JUN 1978
1-1
Operating Instructions-7B92A
and the 7B92A in the B horizontal Information. Fig. 1-1shows the Time/Div Variable and
compartment, the sweep locks up if Mainframe Selectors. Fig. 1-3 shows the front-panel
the 7B92A is in its Alternate mode controls, connectors, and indicators.
and the Mainframe Horizontal mode
is Alt. Lock-up can be avoided by
changing the Mainframe Horizontal MAIN TRIGGERING Controls
mode to Chop or B. This allows both
7B92A sweeps to be displayed. (1) LEVEL Control
To install the 7B92A in a plug-in compartment, Selects amplitude point on trigger signal where sweep
push it in until it fits firmly into the compartment. The triggering occurs when the MAIN TRIGGERING MODE
front panel of the 7B92A should be flush with the front AUTO, NORM, or SINGLE SWEEP switches are
panel of the oscilloscope. Even though the gain of the pressed. When the MAIN TRIGGERING MODE HF
oscilloscope is standardized, the sweep calibration of the SYNC switch is pressed, the LEVEL control adjusts the
7B92A should be checked when installed. The frequency of the trigger generator to synchronize with the
procedure for checking the unit is given under Sweep frequency (or sub-harmonic) of the triggering signal to
Calibration in the Operating Checkout procedure In this provide a stable display.
section.
(2) SLOPE Control
To remove the 7B92A, pull the release latch (see
Fig. 1-2) to disengage the unit from the oscilloscope, and Permits triggering on the positive or negative slope of the
pull it out of the plug-in compartment. trigger signal (except in HF SYNC).
(3) TRIG'D Indicator
When lit, indicates that the sweep is triggered and will
produce a display with correct setting of the POSITION
control and the controls on the associated amplifier plug-
in unit(s) and oscilloscope.
(4) MODE Switches
Select the desired MAIN TRIGGERING mode. Selected
mode is indicated by lighted pushbutton.
AUTO: Selects a triggered sweep initiated by the applied
trigger signal at a point determined by the LEVEL control
and SLOPE control when the trigger signal repetition rate
is above 30 hertz and within the frequency range
selected by the COUPLING switches. When the LEVEL
control is outside the amplitude range, the trigger
repetition rate is outside the frequency range selected by
the COUPLING switches, or the trigger signal is
inadequate, the sweep free-runs to provide a reference
Fig. 1-2. Location of release latch. trace.
HF SYNC: Sweep initiated by trigger signals with
FRONT-PANEL CONTROLS, repetition rates above 100 megahertz and within the
CONNECTORS, AND INDICATORS range selected by the COUPLING switch. Stable display
can be obtained when the LEVEL control adjusts the
All controls, connectors, and indicators required frequency of the trigger generator to the frequency (or
for the operation of the 7B92A, except the Time/Div sub-harmonic) of the trigger signal. When the LEVEL
Variable and Mainframe Selectors, are located on the control is adjusted to frequencies between sub-
front panel. A brief description of the front-panel harmonics, the sweep free-runs.
controls, connectors, and indicators is given here. More
detailed information is given under General Operating
REV B, JUN 1978
1-2
Operating Instructions-7B92A
Fig. 1-3. Front-panel controls and connectors.
NORM: Sweep initiated by the applied trigger signal at a JUN 1978 a trigger is received and the sweep is
point selected by the LEVEL control and SLOPE control completed. The SINGLE SWEEP-RESET switch must
over the frequency range selected by the COUPLING be pressed again before another sweep can be
switches. Triggered sweep can be obtained only over displayed.
the amplitude range of the applied trigger signal. When
the LEVEL control is either outside the amplitude range, (5) COUPLING Switches
the trigger repetition rate is outside the frequency range
selected by the COUPLING switches, or the trigger Select trigger signal coupling. Selected coupling is
signal is inadequate, there is no trace. indicated by lighted pushbutton.
SINGLE SWEEP-RESET: When the SINGLE SWEEP- AC: Rejects dc and attenuates ac signals below about
RESET switch is pressed, a single trace will be 30 hertz. Accepts signals between 30 hertz and 500
presented when the next trigger pulse is received. The megahertz.
SINGLE SWEEP-RESET switch remains lit until REV B,
REV B, JUN 1978
1-3
Operating Instructions-7B92A
AC LF REJ: Rejects dc and attenuates signals below30 ALT Sweep: The Alternate mode is selected when the
kilohertz. Accepts signals between 30 kilohertz and 500 DLY'D Time/Division switch is pulled out and rotated
megahertz. clockwise and the TRACE SEP control is turned
clockwise from the ALT OFF position. In this mode, the
AC HF REJ. Rejects dc and attenuates signals above delaying sweep is displayed (with an intensified zone
50 kilohertz. Accepts signals from 30 hertz to 50 during the time that the delayed sweep runs) alternately
kilohertz. with the delayed sweep.
DC: Accepts all signals from dc to 500 megahertz.
Intensified Sweep: The Intensified mode, a function of
(6) SOURCE Switches the delaying and delayed sweeps is selected when the
Select the triggering source. Selected source is DLY'D Time/Division switch is pulled out and rotated
indicated by lighted pushbutton. clockwise, and the TRACE SEP control is rotated fully
counterclockwise to the ALT OFF position (see Fig. 1-3).
INT: Trigger signal obtained internally from amplifier In this mode, a portion of the delaying sweep is
plug-in unit of oscilloscope. intensified during the time that the delayed sweep
generator runs.
LINE: Trigger signal obtained internally from the line
voltage applied to the oscilloscope. DLY'D Sweep: The Delayed sweep mode is selected
when the DLY'D Time/Division switch is pulled out,
EXT: Trigger signal obtained from an external source rotated for the desired delayed sweep rate, and then
applied to the MAIN TRIG IN connector. pushed in. In this mode, the delayed sweep is displayed
at a rate determined by the DLY'D Time/Division switch
EXT